Process of and composition for waterproofing permeable material



Patented May 4, 1943 PROCESS OF AND COMPOSITION FOR WA- TERPROOFING PERMEABLE MATERIAL Constantine F. Fabian, Brookfield, and James B. Lee, Danbury, Com, assignors to Lee Bros. Hats, Inc., Danbnry, Com, a corporation of Connecticut No Drawing. Application Octoberll, 1939, SerialNo. 298,978

14' Claims. (Cl. 106-268) This invention relates to processes for waterproofing textiles,-felts and other fabricated ma-' terials of a more or less permeable nature and to compositions adapted for such use.

While the invention may be used'for the treatment of a wide range of materials, it has special application to the waterproofing of felt hats. as well as to other articles formed from animal fiber. It may also be advantageously used in the waterproofing of articles made of other fabricated materials, such, for example, as straw hats.

Water repellant qualities have long been recog-' nized through the use of compositions depending on the presence of an aluminum salt of a fatty acid of high molecular weight such, for example,

as aluminum stearate.- Such salt is first dissolved with the aid of heat in a volatile hydrocarbon solvent, such as benzol, naphtha or the' like, with the resultant formation of a thick i amorphous, coagulated, semi-solid gel. Such gelcannot itself be used for water-proofing but must first be dispersed in some kind of a peptizing agent. In its dispersed state the gel forms a pseudo solution or sol, with varying degrees of transparency, viscosity, uniformity and completeness of dispersion and stability. Each of these characteristics, particularly those of completeness; uniformity and stability of dispersion, as well as that of viscosity, is of the greatest importance in producing a practical, effective and satisfactory waterproofing composition. These characteristics have been found to depend largely on the particular dispersing agent employed, the selection of the latter yielding widely different values to the aluminum stearate gel as a waterproofing agent.

In the action of the peptizer on the gel, the molecules of the peptizer, by reason of their capacity to'adhere to the molecular surface of the gel, tend to convert the long chain structure of the gel into a structure characterized by shorter chains. The viscosity of the dispersed gel for any given percentage of weight concentration in also monohydric alcohols, such as methyl alcohol,

ethyl alcohol and butyl alcohol.

The use of amino compounds as dispers agents results not only in an undesirably low viscosity in the dispersed aluminum stearate, but especially in a non-uniformity, incompleteness and instability in the dispersion, the dispersed gel being characterized by the formation of insoluble coagulated flakes, the presence of which interferes with the practical treatment of the material to be waterproofed and prevents the development of the waterproofing capacity of the dispersed aluminum stearate. Such peptizers further impart an alkaline reaction to the solution dispersed flakes which accumulate on or near the surface of the volatile vehicle, interfering with or preventing the practical effective application of the solution to the material to be treated and seriously diminishing the water repellant qualities of the composition. The acidity imparted by such dispersing agents, moreover, is detrimental to the treated material in the case of many articles re,- quired to be waterproofed, and particularly when such articles are to be worn in contact with the skin of the wearer.

The use of monohydric alcohols presents great practical difliculty in securing any uniform dispersion of the gel. the gel immediately precipitates white flaky masses. Even when alcohol'is added to the gel in successive small amounts, these masses can be dispersed only with the greatest difficulty. If alcohol is added in such considerable amounts as must be resorted to in the preparation of the a dispersed gel on a commercial scale, the dispersion of these flaky masses is impracticable, with a resultant coagulation and non-uniformity of dispersion such as to render the compositionunusable. A probable explanation of the formation of the white coagulation inthe case of monohydric alcohols is the presence of hydroxyl groups which are negatively charged (6E). dimensions possess an electric charge-either positive or negative; In the case of aluminum .stearate these particles are positively charged,

and by treatment with alcohols having anegative charge the colloidal particles of aluminum The addition of alcohol to.

It is known that particles of colloidal stearate are neutralized and coagulated. By increasing the negative charge in the peptizer, as

by increasing the number of hydroxyl groups, coagulation isincreased. For example, it has been found that the effectiveness of the dispersion is increasingly diminished when the number of hydroxyl groups in the alcohol'is increased, as by the use of peptizing agents consisting of glycols and glycerines, dihydric and trihydric alcohols.

We have found that a high viscosity, high stability, and a complete uniformity of dispersion are essential to develop the full water repellant capacity of the dispersed gelwhen apties of the aluminum stearate gel by the addition to the dispersed gel of non-oxidizable mineral waxes together with mineral oils.

Another object of the invention is the preservation or intensification of the natural or artificial luster of articles treated by-the composition. This luster tends to be appreciably dulled by theaction of aluminum stearate gel, and especially when the latter is used in combination with oils or waxes. Furthermore, in the case of colored or dyed articles, the color tends to become dulled due to its increased sensitivity to the action of light. By the use of certain softening or modifying agents in combination with the dispersed gel, the delustering action of the composition is oifset, the luster being infact intensified without diminution of the water repellant action of the gel and the increased sensitivity of color to light otherwise present is absent.

Another object is to impart stiffness to certain treated articles simultaneously with the waterproofing treatment. In the case of articles made of materials of vegetable origin, such, for example, as straw hats, the treatment contemplates not only imparting waterproofing qualities but also a certain degree of stiffness in addition to that naturally possessed by the article. This is made possible by treatment of the articles with a plasticizing .agent simultaneously with treatment by the waterproofing composition.

-These and other objects of the invention will be best understood by the following description and the accompanying illustrative examples of one or more methods of carrying it into effect. In carrying out the invention, a gel is first prepared by adding to an aluminum salt, of a fatty acid of high molecular weight a suitable amount of liquid vehicle, which is then heated. Fatty acids which are preferred include oleic, stearic and palmitic, the preferred salt being aluminum stearate. From the aluminum salt the gel is prepared by adding thereto a volatile hydrocarbon solvent, such as benzol, naphtha,

toluol, xylol, carbontetrachloride or the like,

naphtha or benzoi being preferred on account of availability. A suitable proportion has been found to be approximately 12 to 15 parts by weight of the liquid vehicle to one part by It has been found that a full realization of the waterproofing capacity of the aluminum stearate gel, with unusual capacity for the required uniform andstable dispersion of the gel, unlike that resulting from the use of amino compounds, alcohols and acids, may' be had by using as a peptizing agent a liquid organic compound of the type R-O-R containing two identical or different alkyl groups, such as CH3, C2H5 or CaH-r,'united to an oxygen atom and known as ethers. Ethers, such as ethyl ether, C2H5.O.C2H5; dipropyl ether, (CH3.CH2.CH2)2O; and di-isopropyl ether, (CI-Li)2.CH.O.CH(CH3)2, have been found to serve as suitable dispersing agents or peptizers. Through the use of one or more of such compounds, not containing hydroxyl groups, the viscosity of the dispersed gel can be easily controlled, and the dispersed phase of the gel maintained indefinitely in stable form without breakdown, coagulation or precipitation.

The peptizing agent is added to the gel'in such proportions as to secure the required viscosity. These proportions will vary with different materials to be treated and with the quantity of the thinning vehicle subsequently employed, as hereinafter described. For example, to produce a relatively thin dispersion, such as would be required for the waterproofing treatment of felt hats, the peptizer may be added in the order of 1 cc. for each 3 to 5 grams of the gel, depending on the thickness and weight of the felt of which the hat is formed. To'produce a relatively thicker dispersion, such as would berequired for the treatment of straw hats, the peptizer may be added in lesser amounts, such as 1 cccfor each 10 grams of gel.

The dispersed mass of gel (either with or without the addition of the oils, waxes and other substances hereinafter mentioned) is then mixed with a volatile liquid hydrocarbon vehicle to thin the liquid down to a condition adapted for the treatment of the particular article or material to be waterproofed, and depending on the article ample, those known by the trade-name Sovasol #5 and Sovasol #5A, the latter produced by the so-called Houdry process. Preference is given to the use of Sovasol #5, which contains approximately equal proportions of parafllns,

naphthenes and aromatics. It may be observed that naphthaswhich are rich in naphthenes have a low solvency for dispersed aluminum gel, while naphthas whose compositions are balanced or low in aromatics and naphthenes but rich in paraffins provide a high degree of solvency.

Obviously the amount of thinning vehicle employed is subject to wide variation. For such materials as felt, the thinning vehicle may be employed in the proportion of one gallon for each or grams of dispersed gel.

In its thinned condition the liquid composition is ready for application to the materialsto be treated, but may be kept standing in its then state without subsequent coagulation of the dispersed gel or other deterioration.

The solution having been thus'prepared may be applied to the material to be treated by any method which insures its impregnation throughout the material. This treatment is carried out preferably by the immersion of the material in the solution for a sufiicient time to cause the desired degree of penetration. In the case of felt hats, or other articles where it is desired not to add appreciably'to their weight, the immersion and impregnation may be followed by removal of the surplus solution through the aid of a centrifugal drier;

We have further found that not only may a remarkable increase beattained in the waterproofing capacity of the aluminum stearate gel by the use in connection with such gel of suitable proportions of mineral oils and waxes, but that through such use certain disadvantages heretofore resulting from the use of oils and waxes alone may be eliminated.

- For the waterproofing of articles having physical properties, such as color, luster, etc., mineral oils and waxes have been recognized as superior to vegetable and animal 'oilsand waxes due to reactions, such as oxidation, to'which the latter are subject and which result in discoloration and ticles, the natural feed and appearance of which must be preserved. It has heretofore been recognized that the presence of a mineral wax used in combination with the mineral oil effects a certain binding action on the latter, with the result of eliminating in part this sweating tendency of the oil.

The use of the wax, however, not only fails to avoid wholly the subsequent sweating of the oil, but results in another disadvantage particularly important in the case of finely surfaced articles, such as felt hats, in that it imparts to the surface a distinctly waxy or tacky feeling, even in the presence of the oil. Such articles, for example, are felt hats in which we include hats of the type known either as wool or fur." For example, in the case of felt hats which have been waterproofed -by treatment with a composition containing mineral oil and ceresin or parafiin, such hats can be readily identified and distinguished from those untreated by any such composition by the mere waxy feel present on the nap.

Through the combination with the dispersed aluminum stearate gel of suitably balanced proportions of mineral oils with mineral waxes, it has been found through extensive comparative tests that the waterproofing capacity of the composition is increased several times that attainable through the use either of the gel without the oils and waxes or of a composition using the oils and waxes without the aluminum stearate. Furthermore, this combination of mineral oils and waxes with the aluminum stearate gel is found to alter the action of the oils and waxes on the fibers and to eliminate not only all evidences of the sweating arising from the oil butall traces of the waxy or tacky feeling heretofore arising from the presence of the wax. Felt hats, for example, which have been waterpruofed by the use of aluminum stearate gel, combined with mineral oils and mineral waxes, have no waxy feel and are indistinguishabl by the appearance or feel of the nap from those not so waterproofed.

While this phase of the invention is not dependent on any theory, the great increase in the waterproofing capacity of the gel, resulting from the presence ofmineral oils and waxes and the altered action of the mineral oils and waxes through the useof aluminum stearate gel, may

' be due to the direct action of the unsaturated gel, with the resultant formation of complex or- .ganic compounds which act as water repellant reinforcement. N

Where mineral oils and waxes are used in combination with the aluminum stearate gel, they are preferably employed by first melting the wax, adding the oil thereto, stirring the oil and wax together, then adding the resultant mixture to the dispersed gel as soon as the latter has been prepared and while still hot, and before it has been mixed with the thinning liquid, and finally stirring the oil and melted wax with the dispersed gel until a uniform mixture has taken place. a

For mineral waxes, ceresin or parafiin are preferably used, better results being found to follow the use of a high grade of ceresin. White ceresin is desirable, particularly in the case of felt hats or other articles having a color or luster which good viscosity, such as that represented by not less than 200 to 300 seconds at 100 F.'in Saybolts apparatus. For treatment of textiles or felts having delicate colors, a petroleum oil refined up to a white color should be employed.

The proportions of oils and waxes to be used may be widely varied, but it has been found in practice that a high intensification of the water repellant capacity of the composition is had and the oil and waxy evidences eliminated by the use of an amount of wax of the order of approximately that of the weight of aluminum stearate employed and an amount of oil substantiallyv less than that of the weight of the wax, as, for exthat such luster be preserved undiminished.-

Treatment by the aluminum stearate gel, while effecting a high degree of waterproofing, in the case of many articles, such for example as felt and sensitivity, of the decreased.

hats, tends to produce a dull appearance, impairing or offsetting the natural luster. The added use of oils and waxes to secure increased water repellant qualities tends further to the dulling of this luster. We have found thatby the incorporation in the dispersed gel, either with or without the use of the oils and waxes, of certain compounds, which may be termed softeners or lustering agents, no detrimental effect on th water repellent capacity of the treated material results, while the delustering action of the composition is ofiset, the natural luster preserved, and such natural luster in most cases intensified treated material to light i been dispersed in ether.

As luster reinforcing agents, use is preferably made of one or more glycols, such as diethylene gycol, ethylene glycol, propylene glycol and butylene glycol. While glycols are insoluble in ether, they may be satisfactorily incorporated by mixture in the aluminum stearate gel which has When use is made ofsuch luster reinforcing agent, the latter is added to and thoroughly mixed with the dispersed gel when first prepared and before the dispersed gel is mixed with the thinning vehicle.- The amount of such agent required to secure the desired luster reinforcing effect is dependent in part on theamount of aluminum stearate employedto form the gel, and, in the case of the additional use of oil and wax,

also on the amounts of the latter ingredients employed. Where an amount of wax is used approximating that of the aluminum stearate and a substantially lesser amount of oil employed, the glycol will be suflicient if added to the dispersed gel in an amount of the order of from 12 to of the weight of the aluminum stearate.

In the treatment of articles requiring a certain artificial stiffness, such, for example, as straw. hats, such stiffness may be imparted at one and. the same time with the waterproofing treatment by incorporating into the dispersed gel a plasticizer. Numerous plasticizers maybe employed for this purpose. Satisfactory results may be secured by using non-oxidizable plasticizers such as tricresyl phosphate, diamyl phthalate, or natural or synthetic resins, as, for example, polymerized vinyl resins, such as that known by the trade-name Vinylite resin, previously dissolved in acetone or benzol. l

The plasticizer may be used in widely varying amounts dependent on the article to be treated and the degree of stiffness desired in the treated material. In the case of treatment of straw hats, for example, an amount of the plasticizer in the order of from 18 to 50% of the weight of the aluminum stearate provides satisfactory results. A plasticizer may be used with the aluminum stearategel, either with or without the concurrent use of oils and waxes, or the concurrent use of a luster reinforcing agent. Such plasticizer is Example 1 To the hot gel is added from 80 to 200 cc. of ethyl ether, depending on the desired viscosity, and this is thoroughly mixed with the gel until complete dispersion occurs.

The dispersed gel is then dissolved in 5 gallons of athinning liquid consisting of naphtha and carbontetrachloride in the proportion of two parts of naphtha to one part of carbontetrachloride.

The solution is then ready for use in waterproofing treatment.

Example 2 Example 3 To the dispersed gel, as prepared'by any of the preceding examples (with or without use of the oil and wax), and before mixture with the thinning. liquid, there is added an amount of from 6 to 12 rams of diethylene glycol, after which 0 the mixture is dissolved in the thinning liquid,

preferably added to the dispersed gel before the latter has been thinned by the thinning vehicle and stirred into the gel until a uniform mixture results. The plasticizer dissolves readily in the gel sol, and when the composition is used and the treated article dried, leaves a colorless transparent body, producing a stiffening and hardening effect in-the waterproofed material.

In the case of a straw hat, the material of the hat is not only rendered waterproof, but at the,

same time it is stiffened with, its assigned shape and form permanently maintained.

The invention may be illustrated by the following specific examples of the preparation of waterproofingcompositions according to the general principles of the invention and intended for the production of approximately five gallons of the waterproofing solution, this being more temperature,such as one of the order of from the required gel is formed.

whereupon the solution is ready for waterproofing.

- Example 4.For straw hats Example 5.-'-For straw hats The waterproofing solution is prepared in the same manner as in Example 4, but with the use of from 5 to 15 grams of Vinylite resin previously dissolved in benzol instead of diamyl'phthalate.

} Various changes in and departures from the embodiments of the waterproofing composition, as herein exemplified,.may be made, all within the scope of the generic invention, depending in part onv the material to be treated, it being understood that th matter herein set forth is submitted as illustrative and not in a limiting sense.

We claim:

1. The method of preparing a waterproofing composition, which consists in forming a gel from a hydrocarbon vehicle and an aluminum salt of a fatty acid of high molecular weight of the group consisting of oleic acid, stearic acid,

and palmitic acid, dispersing such gel in a pep- 'there is also mixed with the dispersed gel a melted mineral wax and a mineral oil.

3. The method as defined in claim 1, in which there is also mixed with the dispersed gel a luster reinforcing agent consisting of glycol.

4. The method as defined in claim 1.'in which there is mixed with the dispersed gel a melted mineral wax and a mineral oil, and also a luster reinforcing agent consisting of glycol.

' 5. The method of preparing a waterproofing composition for impregnating fur hatsjwhich consists in forming an aluminum stearate hydrostearic, acid, and palmitic acid, said gel being dispersed by and said compositloncontaining an carbon gel, dispersing such gel in liquid aliphatic ether from the group consisting of ethyl ether, dipropyl ether, and di-isopropyl ether, mixing with the dispersed gel mineral wax and mineral oil, afso mixing glycol with such dispersed gel, and thinning the mixture with a volatile fluid hydrocarbon vehicle.

6. The method of preparing a composition for waterproofing and stiffening straw hats, which consists in forming an aluminum stearate hydrocarbon gel, dispersing such gel in liquid aliphatic ether from the group consisting of ethyl ether, dipropyl ether, and di-isopropyl ether,

mixing with such dispersed gel 2. non-oxidizableplasticizing agent, and thinning the mixture with a volatile hydrocarbon vehicle.

7. A liquid waterproofing composition containing a gel formed from a hydrocarbon vehicle and an aluminum salt of, a fatty acidof high molecular weight of the group consisting of oleic acid;

stearic acid, and palmitic acid, said gel-being dispersed by and said composition containing an ether from the group consisting of ethyl ether,

dipropyl ether and di-isopropyl ether.

8. A liquid waterproofing composition contaming a gel formed from a hydrocarbon vehicle and an aluminum salt of a fatty acid of high molecular weight of the group consisting of oleic acid,

ether from the group consisting of ethyl ether,

dipropyl ether, and di-isopropyl ether.

9. The method of making a waterproofing composition which consists in forming a hydrocarbon aluminum stearate gel, dispersing such gel in a liquid aliphatic ether peptizing agent from the group consisting of ethyl ether, dipropyl ether, and di-isopropyl ether, said peptizing agent being added to the gel in the proportions of one cubic centimeter of the peptizing agent to from three to ten grams of the gel.

10. The waterproofing composition as defined in claim 7, and containing also a mineral wax and a mineral oil.

11. The waterproofing composition as defined in claim 7, and containing also cercsin wax in an amount approximating the amount by weight of the aluminum stearate, and containing also mineral oil in'an amount less than that of the 

